With reference to FIG. 1, a turbocharger turbine will generally include a housing 11, and a wheel 13 having a hub 15 and plurality of blades 17. The housing and wheel typically define a fluid passageway serially including a spiral volute portion 21, an inlet passageway 23 radially inward of the volute portion (and usually extending radially), a blade passageway 25 that extends from blade leading edges 27 to blade trailing edges 29, and an outlet passageway 31 that extends downstream from the blade trailing edges. Optionally, the inlet passageway may extend through static or variable vanes 35.
The fluid passageway is serially defined on an inner side by an inlet inner housing wall 33 (throughout the inlet), and by the wheel hub 15 (throughout the blade passageway). The fluid passageway is serially defined on an outer side by an inlet outer housing wall 41 (throughout the inlet), a shroud wall 43 (throughout the blade passageway) that conforms to outer edges 45 of the blades, and an outlet housing wall 47 typically extending cylindrically downstream from the trailing edges to and endpoint. At the endpoint, there is a mechanical connection, such as to an exhaust system or a transition to a second turbine. From the standpoint of airflow, the transition provides an abrupt change to the geometry of the passageway.
A manufacturer of turbochargers, such as vehicle turbochargers, generator turbochargers and the like, may design a turbocharger turbine for production, and wish to sell it to various manufacturers (e.g., vehicle makers). Problematically, each manufacturer will have different requirements for the turbines. These requirements can be in numerous categories, such as flow rates, mechanical efficiency and outlet temperatures.
Accordingly, there has existed a need for a single turbine that can meet varying manufacturing requirements. Preferred embodiments of the present invention satisfy these and other needs, and provide further related advantages.